Resynchronizing system for master and secondary controllers



C. H. BISSELL Feb. 6, 1934.

RESYNCHRONIZING SYSTEM FOR MASTER AND SECONDARY CONTROLLERS Filed Oct. 27, 1930 INVENTOR 54" A TTORNEYS.

t Patented Feb. 6, 1934 UNITED STATES BESYNCHRONIZING SYSTEM FOR MASTER I AND SECONDARY CONTROLLERS Carl H. Bissell, Syracuse, N. Y., assignor to Grouse-Hinds Company, Syracuse, N. Y., a corporation of New York Application October 27, 1930. Serial No. 491,850

2 Claims. (01. 172-293) This invention relates to resynchronizing systems which include a master controller and one or more, preferably a pluralityof secondary con trollers, such as highway traflic signalling systems wherein the signals at a plurality of intersections pass through repeated traflic cycles from go to stop on one street and stop to go on an intersecting street and back to go on the first street and stop on the second street etc., and has for its object a particularly simple means for synchronizing or resynchronizing the system or the signals. It also has for its object a particularly simple and eflicient means for varying the traffic cycle period from a central station. The system is of the general type shown in my application Sr. No. 460,771 filed June 12, 1930. In this invention, however, I make provision whereby the resynchronizing wires of the system may be run through any conduits which may already be laid in the streets, thus avoiding any additional expense of laying special or separate conduits for the wires or cables of the trafllc signal system. It often happens that these conduits already laid in the streets contain telephone wires, and

accordingly, any additional wires placed in the same conduits must carry only such electrical currents as will not interfere with the telephone service. In my present invention, I make such provision whereby the resynchronizing currents w are operated on direct current which is not objectionable to telephone service.

The invention consists in the novel features and in the combinations and constructions hereinaiter set forth and claimed.

In describing this invention, reference is had to the-accompanying drawing in which like characters designate corresponding parts in all the views. I

Figure 1 is a diagrammatic view of the system to which this invention is applicable.

Figure 2 is a schematic diagram of the system showing one master timer and one secondary timer.

Although this resynchronizing system is shown as designed for highway trafllc signalling systems, it is applicable to other systems including units which are to be kept working in synchromsm.

1 designates the main street; 2, 3, 4 and 5 intersecting streets. The signals are arranged at each intersection, and each intersection is provided with a controller. The controller atone intersection is usually a master controller for those at the other intersections; the controllers at the other intersections being secondary controllers, although, all intersections may have secondary controllers and the master controller located at a central station. The secondary controllers are located in suitable cabinets 6 located at each. intersection. The master controller is located in a cabinet 6". The signals are usually green lights for go and red lights for stop and an intermediate warning signal, as an amber light, may also be used.

The signals pass repeatedly through a regular 66 traiilc cycle from green on the main highway to red and from red to green on the intersecting highways. The trafilc cycle period is the extent of time it takes the signals to make one complete cycle, as for instance from green on 70 the main street back to green on the main street. The traflic cycle period may be for instance sixty, ninety or one hundred seconds etc., and the traiiiccycle may be split up into equal divisions as fifty seconds go and stop on each street with a traffic cycle of one hundred secondsor may be split up into unequal divisions as sixty seconds go on one highway and forty seconds stop on the same highway and sixty seconds stop and forty seconds go on the intersecting highway. The dividing up ofthe traflic cycle forms no part of this invention.

The system may be applied in other situations where master and secondary controllers are used.

This resynchronizing system comprises master and secondary controllers, each controller comprising a timer and actuating means therefor, means controlled by the master timer and by the, secondary timer for cutting out or stopping the secondary controllers individually at predetermined intervals and again cutting in the secondary controller or cutting in all the secondary controllers simultaneously.

l1 designates the master controller and 12 one of the secondary controllers. l3 designates the timer shaft of the master controller and the actuating means for the timershaft is usually an electric motor 14. The timer also includes cams mounted on the timer shaft and controlling switches in the signal circuit, which switches control the illuminating of the signal lamps. As the timers of this type are well known andas the timers form no part of this invention, further description is thought to be unnecessary.

15 designates the timer shaft of the secondary timer and 16 the electric motor. The shaft 15 also operates timing means which operate the switches which control the illumination of the signal lamps. The motors are preferably of the induction disk type. 11o

17 designates the driving coils of the motor 14 of the master timer, these being connected to a feed circuit by wires 18, 19. 20 designates the driving coils of the motor of each secondary controller, these being connected in a feed circuit through a branch circuit to be presently described. The master controller 11 is constantly in operation without stopping while the system is in operation, and the secondary controllers are stopped preferably once during each cycle of movement, and again started, all the secondary controllers being started at the same time. The secondary controllers are stopped by cutting out the driving coils by opening the branch circuit to the driving coils 20 of the secondary controller, there being one branch circuit for each controller, and the cutting out of the driving" coils 20 is controlled by timed means, a portion of which is operated by the master controller and a portion by each secondary con-- troller In the illustrated embodiment of my invention, each branch circuit is provided with a normally closed switch 21 in one of the legs 22 thereof, the other leg 23 being connected to the feed circuit. The switch is normally engaged with the contact 24 connected to a conductor 25 leading to the feed circuit. This switch is opened at predetermined intervals by electroresponsive means, as an electro-magnet 210, the coils of which are connected in a resynchronizing circuit, and the how of current through the resynchronizing circuit from the feed line is controlled by switches operated respectively by the master controller and each secondary controller.

26 designates a normally closed switch in the resynchronizing circuit, which switch is normally held closed by the master controller and opened at predetermined intervals or once during each cycle or rotation of the timer shaft 13.

27 designates a normally open switch in the resynchronising circuit, which is closed by the timer shaft 15 of each secondary controller. 28 designates an additional switch, which is normally closed. This is merely a change-over switch to connect the electro-responsive means 210 of any particular secondary controller in one or the other of the two resynchronizing circuits.

The switch 26 consists of a movable switch arm 29 normally engaged with the contact 30 whichisconnectedbyawire 31inthefeed circuit, the switch arm 29 having a follower 32 coacting with a cam 33 on the timer shaft 13. This cam has a comparatively long high or dwell portion and a short low or recess portion 34.

The switch 27 consists of spaced apart contacts 36, 36, a movable arm 37 operable to engage the switch contacts and means as an adjustable oflset arm 38 operable by the timer shaft 15 for engaging the arm 37, once during each rotation of the timer shaft 15 to cause it to bring the contact 35 against the contact 36. The arm 37 is returned to its normal position to permit the switch contacts 35, 36 to separate by a suitable spring when the offset arm 38 moves out of engagement with said am 37. The switch arm 29 of the switch 26 operated by the master controller is connected by a wire 39 through the change-over switch 28, and wire 40 to the contact 35 of the switch 27.

In operation, the switch 26 is normally held closed by the fact that the follower is riding on the long high surface of the cam 33. The arm 33 engages the switch arm 37 before the switch 26 opens the circuit, due to the greater speed of the motor 16 over the motor 14. Thus, the switch contacts 35, 36 are brought together before the follower 32 follows into the recess 34, and hence when the switch 27 is closed by the oifset arm 38 depressing the switch arm 37, the current will flow from the feed circuit through the wire 31, contact 30, switch arm 29, wire 39, switch 28, wire 40, switch 27 to the electro-magnet 210, thence through wire 41 back to the feed circuit. when the electromagnet 210 is energized it attracts its armature 21 and thus opens the feed circuit to the driving coils 20 of the secondary controller so that the secondary controller will stop and remain stopped as long as the follower 32 is engaged with the high portion of the cam 33. When, however, the recess 34 of the cam 33 registers with the follower 32, the resynchronizing circuit will be broken, the magnet 210 deenergized and the switch 21 again closed, thus cutting in the driving coils 20 in the secondary motor, so that the motor again starts. All the motors of the secondary controllers will not be cut out at exactly the same time but they will all start at exactly the same time, and hence all the secondary motors are synchronized with each other and with the master motor. In order to prevent coasting of the secondary motors when their driving coils are cut out, or in order to effect a quick stop of the motors, means is provided for applying a braking force to the secondary controllers less than the driving force. This means is here shown as braking coils 42 for each secondary motor, these being connected in feed wires 43, 43. The resynchronizing circuit is also connected in circuit with these feed wires 43, 43 and in order that the master and secondary motors may rotate at substantially the same ratio of speed, it is to be remembered that the secondary motors must be adjusted to run faster than the master motor. The master motor is also providing with braking coils 44 connected in the feed wires 43, 43.

As the braking coils determine the speed of the motors, they also determine the extent of the trainc cycle and in order to vary the trafllc cycle period, the braking coil circuit is provided with a variable resistance 45. The braking coil circuit is preferably connected to a source of direct current in order that it may be located in a telephone wire conduit, and also in order that the braking coils will apply only a braking force and not tend to actuate the motors in a reverse direction. The variable resistance 45 may be located at any central station as a police station so that traffic cycle periods can be adjusted from that station to suit conditions. The driving coils are preferably connected in an alternating current circuit.

The system is usually provided with two synchronlzing circuits as in some instances it may be desirable to connect some of the secondary controllers in one circuit and others in another, and in order to connect some of the controllers, or the electro-magnets 210 thereof in one synchronizing circuit or another, the switch 28 is provided. The other synchronizmg circuit includes a switch 46 similar to the switch 26 and coacting with the cam 47 similar to the cam 33. The conductor 48 of the synchronizing circuit, corresponding to the conductor 39, is connected to a terminal 49 of the switch 28 while the wire 39 is connected to a terminal 50 of the switch 28. The switch 28 includes an intermediate terminal 51 which normally engages the terminal 50 but which may be shifted to engage the terminal 49 by inserting a plug as52 througha hole 53 in the wall of the casing of the secondary controller, this plug thrusting against a stem 53 on the intermediate contact 51 sufficiently to shift it out of engagement with the terminal 50 into engagement with the contact 49. The plug 52, when not used, is held as shown in a hole in the wall of the casing. This change-over switch forms no part of this invention.

In operation, the traffic cycle period is determined by setting the variable resistance 45, which acts as a brake to retard the rotation of the motors against the driving coils of the motor. Owing to the switches 26 or 46, and 27, the resynchronizing circuits will be closed once during each rotation of the master and secondary timers, and when closed, the circuit through the driving coils of the secondary motors will be opened so that no driving force is applied to the secondary motors and the secondary motors will thence be instantly stopped by the action of the braking coils and will remain stopped until the follower 32 or the corresponding follower of the switch 46 drops into the recess 34 of the cam 33 or the corresponding recess of the cam 47, so that the driving coils of the secondary'motor are again energized and the timer shaft 15 begins another cycle. Immediately upon begirming of the cycle, the off-set arm ratchets past the switch arm 37 permitting the switch 27 to again open so that the resynchronizing circuit remains open when the follower 32 again rides upon the high point of the cam 33 and the resynchronizing circuit remains open until it is again closed by the off-set arm 38 again closing the switch 27. It will be understood that there is a branch circuit for the driving coils of each secondary motor and also an electro-magnet 210, switch 21 and switch 27 for each secondary motor and hence that the off-set arms 38 of all the secondary motors need not close the switches 2''! simultaneously, but that all resynchronizing circuits will be opened simultaneously by the follower 32 registering with the recess 34 of the cam 33 of the master controller.

What I claim is: I

1. In a resynchronizing system including a master controller and a. secondary controller, each controller comprising a timer and an electric motor for actuating the timer, each motor including driving coils to actuate the same, and braking coils acting in opposition to the driving coils, a circuit for energizing the braking coils or both motors, a circuit for energizing the driving coil of the motor 01 the master controller, and a circuit, including a normally closed switch, for energizing the driving coil of the motor of the secondary controller, electro-responsive means operable when energized to open said normally closed switch, a circuit for energizing said electroresponsive means including a normally open switch, a plurality of control circuits, each including a normally closed switch and means operable by the master controller to periodically open each of said last mentioned switches at different relative periods of the cycle of the master controller, and means for selectively connecting one of said control circuits to the circuit of the electro-responsive means, and means operable by the secondary controller to periodically close the normally open switch in the electro-responsive means circuit.

2. In a. resynchronizing system including a master controller and a secondary controller, each controller comprising a timer and an elec tric motor for actuating the timer, each motor including driving coils to actuate the same, and braking coils acting in opposition to the driving 0 coils, a circuit for energizing the braking coils of both motors, a circuit for energizing the driv ing coil of the motor of the master controller, and a circuit, including a normally closed switch, for energizing the driving coil of the motor of the 105 secondary controller, electro-responsive means operable when energized to open said normally closed switch, a circuit for energizing said electro-responsive means including a normallyopen switch. and a plurality of control circuits, each 110 including a normally closed switch and means operable by the master controller to periodically open each of said last mentioned switches at different relative periods of the cycle of the master controller, and means for selectively connecting 5 one of said control circuits to the circuit of the electro-responsive means, and means operable by the secondary controller to periodically close the normally open switch in the electro-responsive means circuit, said last mentioned means 2 being manually acflustable to close said last mentioned switch when the secondary controller assumes one of a plurality of positions relative to the master controller.

CARL H. BISSELL. 

